Taken is Little Cayman
Yes, I'd say that's a Whitefin Sharksucker. I don't think the tail border width is always a great way to distinguish between Echeneis neucratoides and E. naucrates, but in this case I think it's pretty clear. We occasionally see this green variation here, usually while with some reef fish (such as a parrotfish). Interesting that this one chose a cowfish. Nice photo!
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